CN114946129A

CN114946129A - Aggregated wireless power transfer with multiple coils and communication channels

Info

Publication number: CN114946129A
Application number: CN202080093826.0A
Authority: CN
Inventors: V·卡纳卡萨拜; J·伽内什
Original assignee: Hanrim Postech Co Ltd
Current assignee: Hanrim Postech Co Ltd
Priority date: 2019-11-21
Filing date: 2020-11-20
Publication date: 2022-08-26
Also published as: JP2023502979A; US20220416581A1; EP4062542A1; WO2021102310A1; WO2021102310A8; KR20220104016A

Abstract

The present disclosure provides systems, apparatuses, devices and methods, including computer programs encoded on a storage medium, for wireless power transfer. The wireless power transmitting device may transmit a plurality of wireless power signals to a wireless power receiving device configured to combine power from the plurality of wireless power signals. The wireless power receiving device may provide the combined wireless power signal to a load, such as a battery charger or an electronic apparatus. In some implementations, each set of primary and secondary coils may utilize a low power wireless power signal (such as 15 watts or less) according to a wireless charging standard. By combining power from multiple low-power wireless power signals, the wireless power receiving apparatus may support the higher power requirements of the electronic device. A plurality of communication channels may be established between the wireless power transmitting device and the wireless power receiving device.

Description

Aggregated wireless power transfer with multiple coils and communication channels

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims priority from Indian provisional patent application No.201911047528, entitled "AGGREGATED WIRELESS POWER TRANSFER WITH MULTIPLE COILS AND COMMUNICATION CHANNELS" filed on 21/11/2019 AND assigned to its assignee. The disclosure of this prior application is considered to be part of the present patent application and is incorporated herein by reference.

Technical Field

The present disclosure relates generally to wireless power and, more particularly, to aggregated wireless power transfer using multiple coils and communication channels.

Background

Conventional wireless power systems have been developed with a primary purpose of charging batteries in wireless power receiving devices such as mobile devices, small electronic devices, gadgets (gadgets), and the like. In conventional wireless power systems, a wireless power transfer device may include a primary coil that generates an electromagnetic field. When the secondary coil is placed in proximity to the primary coil, the electromagnetic field may induce a voltage in the secondary coil of the wireless power receiving device. In such a configuration, the electromagnetic field may wirelessly transfer power to the secondary coil. Power may be transferred using resonant or non-resonant inductive coupling between the primary and secondary coils. The wireless power receiving device may operate using the received power or may store the received energy in a battery for subsequent use. Conventional techniques for wireless power transfer may not provide sufficient power for newer electronic devices. It is desirable to increase the reliability and amount of power that can be wirelessly transferred to an electronic device.

Disclosure of Invention

The systems, methods, and devices of the present disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

One innovative aspect of the subject matter described in this disclosure can be implemented in a wireless power transfer device. In some implementations, a wireless power transmitting device may include multiple primary coils for transmitting wireless power to different secondary coils of a wireless power receiving device. The plurality of primary coils may include at least a first primary coil and a second primary coil. The wireless power transfer device may include a power signal generator electrically connected to the plurality of primary coils and configured to selectively provide power to the plurality of primary coils. The wireless power transfer apparatus may include a Transmit (TX) controller coupled with a power signal generator and a plurality of primary coils. The TX controller may be configured to control an amount of power provided by the power signal generator to the plurality of primary coils.

In some implementations, the wireless power transmitting device may include one or more communication units communicatively coupled with the TX controller and configured to communicate with a wireless power receiving device. The one or more communication units may enable communication via at least a first communication channel at the first primary coil and a second communication channel at the second primary coil.

In some implementations, the one or more communication units may be configured to receive a first communication from the wireless power receiving device via a first communication channel at the first primary coil. The one or more communication units may be configured to receive a second communication from the wireless power receiving device via a second communication channel at a second primary coil.

In some implementations, the first communication and the second communication are received at different times.

In some implementations, the first communication includes a first identifier to identify the first communication channel and the second communication includes a second identifier to identify the second communication channel.

In some implementations, the TX controller may be configured to detect foreign objects at either the first primary coil or the second primary coil based on the first communication or the second communication, respectively.

In some implementations, the TX controller may be configured to determine a first quality factor (Q factor) for the first primary coil, determine a second Q factor for the second primary coil, obtain a first reference quality value from the first communication, and obtain a second reference quality value from the second communication. The TX controller may be configured to detect the foreign object based on a first comparison of the first Q factor to the first reference quality value or a second comparison of the second Q factor to the second reference quality value.

In some implementations, the TX controller may be configured to obtain, from the first communication, a first received power metric related to wireless power received by a first secondary coil of the wireless power receiving device from the first primary coil. In some implementations, the TX controller may be configured to obtain, from the second communication, a second received power metric with respect to wireless power received by a second secondary coil of the wireless power receiving device from the second primary coil. The TX controller may be configured to determine a first transmit power metric for the first primary coil and determine a second transmit power metric for the second primary coil. The TX controller may be configured to detect the foreign object based on a first comparison of the first transmit power metric to the first receive power metric or a second comparison of the second transmit power metric to the second receive power metric.

In some implementations, the first communication may include a first received power metric with respect to wireless power received by a first secondary coil of the wireless power receiving device from the first primary coil. The second communication may include a second received power metric with respect to wireless power received by a second secondary coil of the wireless power receiving device from the second primary coil.

In some implementations, the one or more communication units may be further configured to transmit a third communication to the wireless power receiving device via either or both of the first primary coil and the second primary coil.

In some implementations, the first communication and the second communication may be received by demodulating an amplitude load modulated signal. The third communication may be communicated by modulating wireless power using frequency modulation.

In some implementations, the amplitude load modulated signal may include Amplitude Shift Keying (ASK) modulation. The frequency modulation includes Frequency Shift Keying (FSK) modulation.

In some implementations, each primary coil may be configured to generate an electromagnetic field for inductively transferring no more than 15 watts of wireless power. The plurality of primary coils may collectively enable wireless power transfer in excess of 15 watts.

In some implementations, the plurality of primary coils may include at least four primary coils, and the plurality of primary coils may collectively enable wireless power transfer of at least 60 watts.

In some implementations, the wireless power transfer device may include one or more switches electrically coupled to at least one of the plurality of primary coils. The one or more switches may be selectively opened by the TX controller to disable the at least one primary coil if the at least one primary coil is not transmitting wireless power to the wireless power receiving device or if a foreign object is detected between the at least one primary coil and the wireless power receiving device.

In some implementations, each primary coil is compatible with a zero-order power (PC 0) rating, and the plurality of primary coils collectively enable wireless power transfer of a primary power (PC 1) rating.

In some implementations, the plurality of primary coils are configured to provide power via more than one primary coil when the wireless power receiving device has a PC1 rated power requirement. In some implementations, the plurality of primary coils are configured to provide power via one primary coil when the wireless power receiving device has a PC0 rated power requirement.

In some implementations, the TX controller is configured to identify whether the wireless power receiving device has the PC0 rated power requirement or the PC1 rated power requirement based at least in part on communications received from the wireless power receiving device via at least one of the plurality of primary coils.

In some implementations, a wireless power transfer device may include a charging surface associated with a plurality of primary coils. The wireless power transfer device may include one or more alignment aids to increase a likelihood that a plurality of secondary coils in the wireless power receiving device will be correspondingly aligned with the plurality of primary coils when the wireless power receiving device is placed on the charging surface.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a wireless power receiving device. In some implementations, a wireless power receiving device may include multiple secondary coils. Each secondary coil may be configured to receive wireless power from a different primary coil of a wireless power transfer device. The plurality of secondary coils may include at least a first secondary coil and a second secondary coil. The wireless power receiving device may include a power combining circuit electrically coupled to the plurality of secondary coils and configured to combine the wireless power from the first secondary coil and the second secondary coil. The power combining circuit may be configured to provide combined wireless power to at least a first load.

In some implementations, a wireless power receiving device may include a Receive (RX) controller coupled with a power combining circuit and a plurality of secondary coils. In some implementations, the wireless power receiving device may include one or more communication units communicatively coupled with the RX controller and configured to communicate with the wireless power transmitting device. The one or more communication units may enable communication via at least a first communication channel at the first secondary coil and a second communication channel at the second secondary coil.

In some implementations, the one or more communication units are configured to transmit a first communication to the wireless power transfer device via a first communication channel at the first secondary coil and transmit a second communication to the wireless power transfer device via a second communication channel at the second secondary coil.

In some implementations, the first communication and the second communication are transmitted at different times.

In some implementations, the first communication includes a first identifier to identify the first communication channel, and wherein the second communication includes a second identifier to identify the second communication channel.

In some implementations, the first communication includes a first received power metric with respect to wireless power received by the first secondary coil from a first primary coil of the wireless power transfer device, and wherein the second communication includes a second received power metric with respect to wireless power received by the second secondary coil from a second primary coil of the wireless power transfer device.

In some implementations, the one or more communication units are further configured to receive a third communication from the wireless power transfer device via either or both of the first secondary coil and the second secondary coil.

In some implementations, the first communication and the second communication are transmitted by modulating an amplitude load modulation signal, and wherein the third communication is received by demodulating the wireless power using frequency modulation.

In some implementations, the amplitude load modulated signal includes Amplitude Shift Keying (ASK) modulation and the frequency modulation includes Frequency Shift Keying (FSK) modulation.

In some implementations, each secondary coil is configured to receive no more than 15 watts of wireless power via an electromagnetic field generated by a different primary coil of the wireless power transfer device, and wherein the plurality of secondary coils collectively receive more than 15 watts of wireless power.

In some implementations, the plurality of secondary coils includes at least four secondary coils, and the plurality of secondary coils collectively receive at least 60 watts of wireless power.

In some implementations, each secondary coil is compatible with the zero order power (PC 0) standard specification, and wherein the plurality of secondary coils collectively receive wireless power of the primary power (PC 1) standard specification.

In some implementations, the wireless power receiving apparatus may include a housing for a plurality of secondary coils, the housing configured to attach to an electronic device. The load may comprise a battery charger of the electronic device.

In some implementations, the wireless power receiving device may include one or more alignment aids to increase a likelihood that the plurality of secondary coils will be correspondingly aligned with a plurality of primary coils associated with a charging surface of the wireless power transmitting device when the wireless power receiving device is placed on the charging surface.

Another innovative aspect of the subject matter described in this disclosure can be implemented in methods performed by a wireless power transfer device. In some implementations, the method may include generating, by a power signal generator, a power signal and providing the power signal to a plurality of primary coils. The method may include transmitting, by the plurality of primary coils, the power signal as wireless power to different secondary coils of the wireless power receiving device. The plurality of primary coils may include at least a first primary coil and a second primary coil. The method may include controlling an amount of power generated by the power signal generator.

In some implementations, the method may include communicating with a wireless power receiving device via at least a first communication channel at a first primary coil and a second communication channel at a second primary coil.

In some implementations, the method may include receiving a first communication from the wireless power receiving device via a first communication channel at a first primary coil, and receiving a second communication from the wireless power receiving device via a second communication channel at a second primary coil.

In some implementations, the method may include detecting a foreign object at either the first primary coil or the second primary coil based at least in part on the first communication or the second communication, respectively.

In some implementations, the first communication includes a first received power metric with respect to wireless power received by a first secondary coil of the wireless power receiving device from a first primary coil, and the second communication includes a second received power metric with respect to wireless power received by a second secondary coil of the wireless power receiving device from a second primary coil.

In some implementations, the method may include transmitting a third communication to the wireless power receiving device via either or both of the first primary coil and the second primary coil.

In some implementations, the first communication and the second communication are received by demodulating an amplitude load modulated signal, and wherein the third communication is communicated by modulating wireless power using frequency modulation.

In some implementations, the amplitude load modulated signal includes Amplitude Shift Keying (ASK) modulation, and wherein the frequency modulation includes Frequency Shift Keying (FSK) modulation.

In some implementations, each primary coil is compatible with the zero-order power (PC 0) standard specification, and wherein the plurality of primary coils collectively implement the wireless power transfer of the primary power (PC 1) standard specification.

In some implementations, the method may include: selectively opening one or more switches coupled to the plurality of primary coils to disable the at least one primary coil if the at least one primary coil is not transmitting wireless power to the wireless power receiving device or if a foreign object is detected between the at least one primary coil and the wireless power receiving device.

Another innovative aspect of the subject matter described in this disclosure can be implemented in methods performed by a wireless power receiving device. In some implementations, the method may include receiving wireless power from a wireless power transfer device through a plurality of secondary coils. Each secondary coil may be configured to receive wireless power from a different primary coil of a wireless power transfer device. The plurality of secondary coils may include at least a first secondary coil and a second secondary coil. The method may include combining, by a power combining circuit, wireless power from the first secondary coil and the second secondary coil to form combined wireless power. The method may include providing combined wireless power to at least a first load.

In some implementations, the method may include communicating with a wireless power transfer device via at least a first communication channel at a first secondary coil and a second communication channel at a second secondary coil.

In some implementations, the method may include transmitting a first communication to the wireless power transfer device via a first communication channel at a first secondary coil, and transmitting a second communication to the wireless power transfer device via a second communication channel at a second secondary coil.

Drawings

The details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims. Note that the relative dimensions of the following figures may not be drawn to scale.

Fig. 1 illustrates an overview of components associated with an example wireless power system, in accordance with some implementations.

Fig. 2 illustrates a pictorial diagram of an example wireless power reception device having multiple secondary coils for receiving wireless power from a wireless power transfer device, according to some implementations.

Fig. 3 illustrates a pictorial diagram of an example wireless power transfer device having multiple primary coils for transferring wireless power to a wireless power receiving device, according to some implementations.

Fig. 4 illustrates an illustrative diagram of an example wireless power system in which a wireless power receiving apparatus is configured to provide power to an electronic device, according to some implementations.

Fig. 5 illustrates a block diagram of an example wireless power transfer apparatus in accordance with some implementations.

Fig. 6 illustrates a block diagram of an example wireless power receiving device, in accordance with some implementations.

Fig. 7 illustrates an example of multiple communication channels between an example wireless power receiving device and an example wireless power transmitting device according to some implementations.

Fig. 8 illustrates an example process for foreign object detection based on the example communication channel described with reference to fig. 7.

Fig. 9 illustrates another example of using multiple communication channels between an example wireless power receiving device and an example wireless power transmitting device, according to some implementations.

Fig. 10 illustrates a flow diagram of an example process for wireless power transfer according to some implementations.

Fig. 11 illustrates a flow diagram of an example process for wireless power reception, according to some implementations.

Fig. 12 illustrates a block diagram of an example device for use in a wireless power system, in accordance with some implementations.

Like reference numbers and designations in the various drawings indicate like elements.

Detailed Description

The following description is directed to certain implementations for the purpose of describing the innovative aspects of the present disclosure. However, one of ordinary skill in the art will readily recognize that the teachings herein may be applied in a number of different ways. The described implementations may be implemented in any component, device, system, or method for transmitting or receiving wireless power.

A conventional wireless power system may include a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may include a primary coil that transfers wireless energy (as a wireless power signal) to a corresponding secondary coil in the wireless power receiving device. A primary coil refers to a wireless energy source (such as inductive or magnetic resonance energy) in a wireless power transfer device. The secondary coil is located in the wireless power receiving device and receives wireless energy. In some conventional wireless power systems, the primary coil may transfer wireless energy to the secondary coil up to a rating predetermined by a wireless standard. For example, the low power wireless power signal may deliver 5 watts (5W), 9W, 12W, or 15W. The Wireless Power Consortium (WPC) is a standard development organization that defines zero-order power (PC 0) as a wireless power system that can support wireless power transfer ratings of up to 15 watts. Thus, a low power wireless power system can deliver up to 15 watts of energy suitable for many electronic devices.

Higher power wireless systems are being developed to support wireless power transfer to electronic devices requiring more power (greater than 15W). For example, a laptop computer, monitor, appliance, or other electronic device may use 65W, 90W, or 120W. WPC defines primary power (PC 1) as a wireless power system capable of supporting wireless power transfer ratings above 15W. Of concern with higher power wireless systems is the amount of electromagnetic interference (EMI) that high power wireless systems may cause. Undesirable EMI or radiation may be caused by excessive magnetic flux not linked to the secondary coil. Furthermore, the use of larger primary coils and larger secondary coils may support higher power transfer, but result in reduced sensitivity to foreign object detection. For example, a larger primary coil may be less able to detect small foreign objects. Further, larger primary coils may result in lower misalignment tolerances compared to smaller primary coils.

Various implementations generally involve using multiple primary coils to simultaneously transfer wireless power to different secondary coils. According to the present disclosure, a wireless power system may utilize a plurality of primary coils and secondary coils to transfer wireless power from a wireless power transmitting device to a wireless power receiving device. For example, each primary coil may transmit a low power signal (15W or less) to a corresponding secondary coil. The wireless power receiving device may combine wireless power from the plurality of secondary coils to provide high power wireless power to the load. For example, the wireless power receiving device may combine 15W from each of the six secondary coils to provide a 90W power signal to the electronic device.

In some implementations, the wireless power transmitting device and the wireless power receiving device may be manufactured according to standardized wireless power specifications (such as the Qi specifications developed by WPC). For example, the wireless power transfer device may comprise a plurality of primary coils, wherein each primary coil may comply with the PC0 design of the Qi specification. The wireless power receiving device may comprise a plurality of secondary coils, wherein each secondary coil may comply with the PC0 design of the Qi specification. Thus, the PC1 power requirement (above 15W) can be met by combining multiple PC0 wireless power channels.

In some implementations, a wireless power transfer device with multiple PC0 primary coils may provide flexibility to wirelessly power different types of wireless power receiving devices. For example, if the wireless power receiving device has one PC0 secondary coil and is placed on one PC0 primary coil (of the wireless power transmitting device), the wireless power transmitting device can supply wireless power according to the conventional PC0 system. However, if the wireless power receiving device has multiple PC0 secondary coils (which can be combined to support the PC1 rating), the wireless power transmitting device may supply wireless power using multiple PC0 primary coils coupled to multiple PC0 secondary coils (or wireless power receiving device) to support the PC1 rating. In some implementations, the wireless power transfer device may support simultaneous charging of multiple PC0 wireless power receiving devices or a combination of PC0 and PC1 wireless power receiving devices.

In some implementations, the wireless power transmitting device and the wireless power receiving device may communicate via multiple communication channels. For example, the first communication channel may include a first primary coil of a wireless power transmitting device and a first secondary coil of a wireless power receiving device. The first communication channel may be used for communication from the wireless power receiving device to the wireless power transmitting device using amplitude load modulation (such as amplitude shift keying) at the first secondary coil. The second communication channel may include a second primary coil of the wireless power transmitting device and a second secondary coil of the wireless power receiving device. The wireless power receiving device may communicate with the wireless power transmitting device using amplitude load modulation at the second secondary coil. For forward communication (from the wireless power transfer device to the wireless power receiving device), the wireless power transfer device may use frequency modulation of the signal applied to the primary coil. The present disclosure includes several examples of communication channels and communications that may be performed using amplitude modulation, frequency modulation, or both.

In other examples, communication channels may be used to communicate information regarding identification information, capabilities, charge status, and control signals, among others. For example, the wireless power receiving device may transmit information about a receiver type, a power capacity, a number of secondary coils, an identification of the secondary coils (such as an Identifier (ID) tag), a load voltage, a charging state, and power received from each of the secondary coils. The wireless power receiving device may transmit a control signal or message to request adjustment of the power level.

In some implementations, the communication path from the wireless power receiving device to the wireless power transmitting device may be referred to as a reverse communication path. In contrast, the communication path from the wireless power transmitting device to the wireless power receiving device may be referred to as a forward communication path. A wireless power transfer device may use one or more forward communication paths to communicate information about transmitter capabilities, power transfer operating points, and responses to control signals. For example, the wireless power transmitting device may use different responses to indicate whether the wireless power transmitting device acknowledged, rejected, or not understood the control or information signal from the wireless power receiving device. In some implementations, each reverse or forward communication path may be associated with a channel ID (also referred to as a tag ID) that uniquely identifies the transmission coil pair (formed by the primary coil and the corresponding secondary coil). A channel ID or tag ID may be included in the communication between the wireless power receiving device and the wireless power transmitting device such that power metrics, reference values, quality measurements, or other information may be specific to the transmit coil pair.

In some implementations, such as the illustrative examples of the present disclosure, one or more forward communication paths may use a first type of modulation and one or more reverse communication paths may use a second type of modulation. For example, Frequency Shift Keying (FSK) modulation may be used on the forward communication path, while Amplitude Shift Keying (ASK) modulation may be used on the reverse communication path. The modulation types described in this application are for illustrative purposes and alternative modulation types may be used within the scope of the present disclosure.

In certain implementations, the designs in the present disclosure may improve foreign object detection. For example, foreign object detection may be performed independently for each transmission coil pair (primary coil and corresponding secondary coil). For example, the communication channel may be used to communicate a reference quality factor, a received power metric, or other information associated with each transmit coil pair. Each PC0 transmits information about the coil pairs that can be used to detect foreign objects or inefficient alignment of the coil pairs. Unlike the single coil PC1 design, the design in this disclosure uses multiple PC0 channels, with wireless power transfer being distributed by multiple PC0 transmission coil pairs. As a result, each PC0 transmission coil pair may have a higher sensitivity to foreign objects than a large coil pair that allocates higher power in a single PC1 channel. The higher sensitivity of foreign object detection for the PC0 transmission coil pair facilitates detection of foreign objects near the transmission coil pair. Further, in some implementations, one or more of the PC0 primary coils may be disabled after detecting the foreign object, while other ones of the PC0 primary coils may continue to transfer wireless power without the foreign object affecting their corresponding PC0 channels.

Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. In some implementations, the described techniques can be used to combine wireless power received from multiple secondary coils to generate a high power output to a load. The wireless power system may cause less EMI and provide better efficiency of wireless power transfer than conventional wireless power systems that use only one wireless power signal. The electronics in both the wireless power transmitting apparatus and the wireless power receiving apparatus can utilize a modular design with components having smaller power ratings. Advantageously, implementations of the present disclosure can support higher power for appliances and electronic devices that require greater amounts of power. The cost and complexity of a wireless power system may be reduced by using multiple low power wireless power signals to accommodate greater wireless power transfer. Furthermore, the use of multiple communication channels may support better in-band communication for robust foreign object detection and sensitivity.

Fig. 1 illustrates an overview of components associated with an example wireless power system, in accordance with some implementations. The wireless power system 100 includes a wireless power transfer device 110 having a plurality of primary coils 120. Each of the primary coils 120 may be associated with a power signal generator. For example, the first primary coil 121 may be electrically coupled with the power signal generator 145. Each primary coil may be a wired coil (wire coil) that transmits a wireless power signal, which may also be referred to as wireless energy or an electromagnetic field. The primary coil may transfer wireless energy using an inductive or magnetic resonance field. The power signal generator may include components (not shown) for preparing the wireless power signal. For example, the power signal generator 145 may include one or more switches, drivers, capacitors in series with each coil, or other components. The wireless power transfer apparatus 110 may include a power source 140 configured to provide power to a power signal generator 145. The power source 140 may convert Alternating Current (AC) to Direct Current (DC). The power source 140 may be internal or external to the wireless power transfer device 110. In some implementations, the primary coil 120 may be coupled with the power signal generator 145 via one or more switches such that each primary coil can be independently enabled or disabled by the TX controller 130.

The primary coil 120 may be managed by one or more controllers, such as a Transmit (TX) controller 130, which controls whether the primary coil is transmitting wireless power. In fig. 1, TX controller 130 may manage power signal generator 145 and may also manage one or more switches (not shown) that enable or disable particular primary coils. TX controller 130 may also be communicatively coupled to one or more communication units, such as a first channel communication unit 131, a second channel communication unit 132, and a system communication unit 133. The

communication units

131, 132, and 133 may be external to the TX controller 130 (as shown), or may be implemented within or within the TX controller 130.

In some implementations, each primary coil may be associated with a different driver, voltage regulator, or the like. In some implementations, each primary coil may be coupled with a separate circuit component, such as a capacitor (in series with the primary coil), a current sense resistor, or other element. TX controller 130 may determine whether to cause a particular primary coil to transmit wireless power. For example, TX controller 130 may periodically activate one or more switches associated with each primary coil (and series capacitor) to stimulate (or briefly energize) the primary coil. TX controller 130 may perform a coil current sensing process to determine whether the wireless power receiving device is located near the primary coil. If a wireless power receiving device is detected, TX controller 130 may activate one or more switches associated with the primary coil to cause the primary coil to transmit wireless power.

A controller, such as TX controller 130, may be configured to detect the presence or proximity of a wireless power receiving device. For example, TX controller 130 may cause one or more primary coils to periodically transmit detection signals and measure changes in coil current or load indicative of objects in the vicinity of the primary coils. In some implementations, the TX controller 130 can detect ping, wireless communication, load modulation, etc., to determine that the secondary coil of the wireless power receiving device is near the primary coil.

Fig. 1 also shows a wireless power receiving device 150. The wireless power receiving device may be any type of apparatus capable of receiving wireless power including a mobile phone, a computer, a laptop, a peripheral device, a widget, a robot, a vehicle, etc. The wireless power receiving device 150 may have an array of secondary coils 160, including a first secondary coil 161 and a second secondary coil 162. The secondary coils 160 may each be capable of receiving wireless power from a different primary coil. For example, when the first secondary coil 161 is located near the first primary coil 121, the first secondary coil 161 may receive wireless power from the first primary coil 121. During the detection phase, the first primary coil 121 may transmit a detection signal (which may also be referred to as a ping). The coil current at the first primary coil 121 may be measured to determine whether the coil current has exceeded a threshold indicative of an object in the electromagnetic field of the first primary coil 121. If an object is detected, the TX controller 130 (or the first channel communication unit 131) may wait for a handshake signal (such as a signal strength packet, an identification signal, or a setting signal, in other examples) from the wireless power receiving device 150 to determine whether the object is a wireless power receiving device or a foreign object. The handshake signals may be communicated by the wireless power receiving device 150 using a series of load changes, such as load modulation. The load change may be detected by the sensing circuit and interpreted by the first primary coil 121. In some implementations, the load change is generated by load amplitude modulation using the first channel communication unit 181 of the wireless power reception apparatus 150. The first channel communication unit 131 may interpret the change in the load to restore the communication from the wireless power receiving apparatus 150. The communication may include information such as a charging level, a requested voltage, a received power, a receiver power capability, support for a wireless charging standard, and the like.

In the wireless power receiving device 150, each of the secondary coils 160 may be part of a separate Receive (RX) circuit. For example, each RX circuit may include one or more secondary coils, rectifiers, DC capacitors, and other components (not shown). Each secondary coil 160 that is properly aligned may generate an induced voltage based on a wireless power signal received from one of the primary coils 120. A capacitor (not shown) may be connected in series between the secondary coil and the rectifier. The rectifier may rectify the voltage and provide the voltage to a power combining circuit 185 that combines power from multiple secondary coils. The power combining circuit 185 may provide combined wireless power to a load 190, such as a battery module (not shown). The load 190 may be in the wireless power receiving apparatus 150 or may be an external device coupled through an electrical interface, such as the power output 187 of the wireless power receiving apparatus 150. The load 190 may include a charger stage, protection circuitry such as temperature detection circuitry, and over-voltage and over-current protection circuitry.

In some implementations, the wireless power transmitting device 110 or the wireless power receiving device 150 may have an alignment mechanism to ensure that the plurality of secondary coils 160 and the plurality of primary coils 120 are properly aligned. The alignment mechanism may include physical guides, trays, magnetic alignment or receptacles, among other examples. In some implementations, the fixed alignment may ensure that the plurality of primary coils and the plurality of secondary coils are aligned to support high aggregate wireless power transfer from the plurality of primary coils 120 to the plurality of secondary coils 160.

Returning to the communication capability, the wireless power transfer device 110 may have a Receive (RX) controller that monitors the power combining circuit 185 and communicates information about the load or charge state. The RX controller 180 may communicate using the first channel communication unit 181, the second channel communication unit 182, or both. Similarly, the RX controller 180 may receive communications from the wireless power transfer apparatus 110 via the system communication unit 183. The system communication unit 183 may sense the voltage at the AC terminals of one or both of the

rectifiers

171 and 172. In some implementations, a forward communication path (from the system communication unit 133 via the power signal generator 145 to the

rectifiers

171 and 172 and the system communication unit 183) may be used for communication from the wireless power transmitting device 110 to the wireless power receiving device 150. A reverse communication path, such as a first path including the first channel communication unit 181 and the first channel communication unit 131, may be used for communication from the wireless power receiving apparatus 150 to the wireless power transmitting apparatus 110. The second path may include the second channel communication unit 182 and the second channel communication unit 132. The first and second reverse communication paths may be used for quality metrics or received power metrics with respect to a particular pair of primary and secondary coils.

In several examples of the present disclosure, the reverse communication path may use ASK modulation, while the forward communication path may use FSK modulation. The modulation type for each path may be different or opposite, so long as the modulation used in the reverse communication path and the forward communication path do not interfere with each other. Further, while several examples illustrate the use of a single forward communication path, in some implementations, each transmit coil pair (formed by a primary coil and a secondary coil) may create separate forward and reverse communication paths.

Fig. 2 illustrates a pictorial diagram of an example wireless power receiving device 150 having multiple secondary coils for receiving wireless power from a wireless power transfer device, according to some implementations. The amount and arrangement of the secondary coils are provided as examples. Other quantities, numbers of layers, or arrangements of secondary coils are also possible. Although shown as a laptop computer, the wireless power receiving apparatus 150 may be any type of electronic device. Further, the wireless power receiving apparatus 150 may be a component integrated into the electronic device, or may be an external component or accessory coupled to the electronic device. In fig. 2, the wireless power receiving device 150 may be manufactured such that it can be positioned on a charging surface (not shown) such that the plurality of secondary coils 160 are configured to receive wireless power. Inside the wireless power receiving device 150 (such as inside the bottom surface portion 255 of the laptop computer), there are a plurality of secondary coils 160 for receiving wireless power.

When the secondary coil and the primary coil are aligned to transfer wireless power, they may form a transmission coil pair. Each transmission coil pair may transfer wireless power according to technical standard specifications. In some implementations, each transmission coil pair may be a low power transfer rate PC0 design that conforms to technical standard specifications. By combining power from multiple PC0 transmit coil pairs, the wireless power receiving device 150 may receive a higher aggregate amount of wireless power, such as those required by the PC1 design.

There may be various ways to align the wireless power receiving device 150 with the wireless power transmitting device such that the plurality of secondary coils 160 may be aligned with a corresponding plurality of primary coils in the wireless power transmitting device. In some implementations, the wireless power transmitting device 110 or the wireless power receiving device 150 (or both) may include an alignment aid to increase the likelihood that the plurality of secondary coils 160 will align with the corresponding plurality of primary coils when the wireless power receiving device 150 is placed on the charging surface of the wireless power transmitting device 110. Alignment aids may include any one or combination of magnetic alignment, physical structure, visual marking, optical alignment aids, acoustic alignment aids, and the like.

Fig. 3 illustrates a pictorial diagram of an example wireless power transfer device having multiple primary coils for transferring wireless power to a wireless power receiving device, according to some implementations. The example wireless power transfer device 110 includes 6 primary coils (shown in section 315). The amount and arrangement of the primary coils are provided as examples. Other quantities, layers or arrangements of primary coils are also possible. The charging surface may house a primary coil. The wireless power receiving device may be placed on the charging surface 315. The first set of primary coils 120 may be activated to transfer wireless power to corresponding secondary coils (not shown) in the wireless power receiving device.

In some implementations, the wireless power transmitting device or the wireless power receiving device (or both) may implement overlapping coils. The pattern of overlapping coils may reduce the amount of area to which the wireless power signal is exposed (or not aligned with the secondary coil). This may have the result of reducing EMI. Alternatively or additionally, the coils may be spaced apart such that multiple coils may be energized without affecting nearby coils. For example, in some implementations, the distance between the centers of any two primary coils may be greater than 1.5 times the maximum diameter of the largest primary coil.

By transmitting wireless power using multiple primary coils 120, the aggregate wireless power transmitted may be higher while maintaining a lower amount of wireless power contributed by each primary coil. The lower power transmission of each primary coil may reduce the amount of EMI and other interference to other components of the wireless power receiving apparatus (or the electronic devices it powers). Thus, in some implementations, using multiple transmission coil pairs may be preferable to using a single large coil to transmit high power wireless signals.

The wireless power transmitting device 110 may be configured with grooves, notches, magnets, or line markings, among other examples, to assist in the alignment of one or more wireless power receiving devices. For example, the alignment design may allow a single wireless power receiving device to be placed on the charging surface 315 such that the plurality of primary coils 120 are aligned with a corresponding plurality of secondary coils in the wireless power receiving device. Alternatively or additionally, charging surface 315 may support wireless charging of wireless power receiving devices of different sizes. For example, the charging surface 315 may be used with wireless power receiving devices that support either or both of the PC0 design or the PC1 design. In some implementations, a phone or other small electronic device may receive wireless power from a subset of the plurality of primary coils 120 according to a PC0 design. According to the PC1 design, which aggregates wireless power from multiple PC0 transmission coil pairs, a laptop or other larger electronic device may receive wireless power from a larger subset or all of the multiple primary coils 120.

Fig. 4 illustrates an illustrative diagram of an example wireless power system 400 in which a wireless power receiving apparatus is configured to provide power to an electronic device, according to some implementations. In fig. 4, the wireless power receiving device 150 may be a wireless power pad having a plurality of secondary coils 160. In the example of fig. 4, the secondary coils are arranged in a non-overlapping pattern. The wireless power-receiving device 150 may have an electrical interface 455 or other connection that provides power from the wireless power-receiving device 150 to the electronic apparatus 450. In some implementations, a fastener 457 (such as a clip, magnet, button, housing, etc.) may be used to physically couple the wireless power receiving apparatus 150 to the electronic device 450. The fastener 457 may be part of the wireless power receiving apparatus 150, the electronic device 450, or both. For example, the wireless power receiving device 150 includes a housing containing a secondary coil, and the housing may be attached to a laptop computer or a tablet computer.

Fig. 5 illustrates a block diagram 500 of an example wireless power transfer device 110 according to some implementations. The first primary coil 121 may have a capacitor 123 and a switch 125 for selectively enabling or disabling wireless power transfer via the first primary coil 121. Similarly, the second primary winding 122 may have a capacitance 124 and a switch 126. The amount of primary coils shown in fig. 5 is for illustrative purposes, and other designs may use a larger number of primary coils (not shown). In some implementations, each of the primary coils may be designed to transmit power according to PC0, and the aggregate amount of wireless power transmitted may support PC1 or greater wireless power requirements. TX controller 130 may control

switches

125 and 126 and the amount of power generated by power signal generator 145. The power signal generator 145 is expanded to show an example of a circuit that may include a diode and a switch. In addition, the TX controller 130 may control switches in the power signal generator 145 to manage the amount or frequency of voltage, etc.

The system communication unit 133 may use frequency modulation, such as Frequency Shift Keying (FSK) modulation, at the power signal generator 145 to communicate via the forward communication path. The first channel communication unit 131 and the second channel communication unit 132 may be coupled to at least a portion of the first primary coil 121 and the second primary coil 122, respectively. The first channel communication unit 131 and the second channel communication unit 132 may include an amplitude demodulator, such as an Amplitude Shift Keying (ASK) demodulator, to receive load modulation communication via the respective

primary coils

121 and 122.

In the design shown in fig. 5, there may be two reverse communication paths (using the first channel communication unit 131 and the second channel communication unit 132) and one forward communication path (using the system communication unit 133). In other configurations, there may be a separate communication unit (similar to the system communication unit 133) for each of the

primary coils

121 and 122.

Fig. 6 illustrates a block diagram 600 of an example wireless power receiving device 150 according to some implementations. The first secondary coil 161 may have a first channel communication unit 181 including an amplitude modulator. The RX controller 180 may control the switches in the first channel communication unit 181 to create load modulation and thus communicate with the wireless power transfer device via the first channel (which includes the first secondary coil 161). Similarly, the second secondary coil 162 may have a separate second channel communication unit 182 having an amplitude modulator for a second channel controlled by the RX controller 180. Each of the

secondary coils

161 and 162 may be connected to a

corresponding rectifier

171 and 172, respectively. The switch 610 in the wireless power receiving device 150 may be capable of disconnecting the load. For example, in other examples, the load may be disconnected to enable calibration of the system to detect foreign objects prior to power transfer, isolate the system during any faults on the load side, protect the load from faults in the system, or keep the load disconnected until an initial handshake with the wireless power transfer device is completed.

The system communication unit 183 may be coupled to AC terminals of either or both of the

rectifiers

171 and 172. The system communication unit 183 may receive and demodulate frequency modulated (such as FSK) communications from a corresponding modulator of a wireless power transfer device (such as the device shown in fig. 5). Accordingly, the system communication unit 183 may receive forward path communication (from the wireless power transmitting apparatus to the wireless power receiving apparatus 150). The system communication unit 183 may transmit the received communication to the RX controller 180. The RX controller 180 may have a control line (not shown) to each of the first channel communication unit 181 and the second channel communication unit 182 and use the channel communication unit for a reverse communication path to the wireless power transmission apparatus.

Fig. 7 illustrates an example 700 of multiple communication channels between an example wireless power receiving device and an example wireless power transmitting device according to some implementations. A first communication channel 751 (using reverse channel load modulation) may include the first secondary winding 161 and the first primary winding 121. The first communication channel 751 may use amplitude modulation (such as ASK modulation). The second communication channel 752 may include the second secondary coil 162 and the second primary coil 122. The second communication channel 752 may also use amplitude modulation. The first communication channel 751 and the second communication channel 752 may both be referred to as back channels because they provide a technique for communication from the wireless power receiving device 150 to the wireless power transmitting device 110. The third communication channel 753 can be referred to as a forward channel because it provides a technique for communication from the wireless power transmitting device 110 to the wireless power receiving device 150. The third communication channel 753 can include frequency modulation (such as FSK modulation) of wireless signals. A third communication channel 753 can use either or both of the

primary coils

121 and 122 to transmit FSK modulated communications that can be picked up by the

secondary coils

161 and 162, respectively.

Fig. 8 illustrates an example process for foreign object detection based on the example communication channel described with reference to fig. 7. Fig. 8 includes the same elements as described in fig. 8 except that a foreign object 810 is added near the PC0 transmission coil pair including the first primary coil 121 and the first secondary coil 161. In other examples, foreign object 810 may be any type of object that affects wireless power transfer via a pair of transmission coils, such as a key, a paperclip, a magnet, or a wire, among others. For example, the foreign object 810 may have ferrite or metallic properties that affect electromagnetic waves for wireless power transfer. Fig. 8 may be used to describe at least two example processes for foreign object detection.

The first process for foreign object detection may be based on quality factor measurements performed prior to the power transfer phase. Typically, prior to the power transfer phase, the wireless power receiving device 150 and the wireless power transmitting device 110 may exchange some information regarding the quality factor of the power transfer. Changes in the primary coil environment, such as the presence of foreign objects, may cause a decrease in the inductance measured at the primary coil terminals or an increase in its equivalent series resistance, or both. These effects of the environment can cause the quality factor (Q factor) of the primary coil to decrease. In order for the wireless power transmitting apparatus 110 to determine whether the measured Q-factor reduction is due to the combination of the wireless power receiving apparatus 150 and the foreign object 810, the wireless power receiving apparatus 150 may provide the reference quality factor to the wireless power transmitting apparatus 110. The reference quality factor consists of the ideal Q factor of a laboratory test, which can be measured at the terminals of the primary coil of a standard test power transmitter if the wireless power receiving device 150 is correctly aligned and there is no foreign object nearby. The reference quality factor is based on the quality of the wireless power receiving apparatus 150 due to a calibration or manufacturing process. The wireless power receiving device 150 may store the reference quality factor and send the reference quality factor in a communication to the wireless power transmitting device 110 prior to the power transfer phase. In the present disclosure, each

secondary coil

161 and 162 may communicate their reference quality factor via

reverse communication channels

751 and 752, respectively. The TX controller 130 of the wireless power transfer device 110 can compare the reference quality factors of the

secondary coils

161 and 162 with the measured Q factors of the corresponding

primary coils

121 and 122. For example, for each primary coil, upon detecting the presence of a receiver, TX controller 130 may determine the Q factor as a ratio of the voltage across the primary coil to the voltage applied to the resonant tank on the transmitter side. TX controller 130 may compare each Q factor to a reference quality factor from the wireless power receiving device for each corresponding secondary coil. In the example of fig. 8, the Q factor of first primary coil 121 may be significantly lower than the reference quality factor of first secondary coil 161 due to the presence of foreign object 810. In contrast, if the foreign object 810 does not affect the transmission coil pair including the second primary coil 122 and the second secondary coil 162, the Q factor of the second primary coil 122 may be close to the reference quality factor of the second secondary coil 162.

When the Q factor of the first primary coil 121 is lower than the reference quality factor of the first secondary coil 161 by a threshold amount, the TX controller 130 may determine that a foreign object 810 exists near the first transmission coil pair. When the Q factor of the second primary coil 122 is not lower than the reference quality factor of the second secondary coil 162 by a threshold amount, the TX controller 130 may determine that a foreign object 810 is not present near the second transmission coil pair. Therefore, the TX controller 130 can detect foreign substances individually for each transmission coil pair. The Q factor sensitivity (variation) for each PC0 transmission coil pair in the presence of foreign object 810 may be higher than the Q factor sensitivity for the PC1 transmission coil pair using the larger coil. The higher sensitivity to changes in the Q-factor of the PC0 transmission coil pair facilitates detection of foreign objects near the transmission coil pair. In response to detecting a foreign object 810 near the first transmission coil pair, the TX controller 130 may disable the first primary coil 121. If foreign object 810 does not affect the second transmission coil pair, TX controller 130 may maintain wireless power transfer via second primary coil 122.

The second process for foreign object detection may be based on power loss accounting during the power transfer phase. For example, during the power transfer phase, RX controller 180 may measure the voltage and current of the wireless power received at each

secondary coil

161 and 162. The measurements at each

secondary coil

161 and 162 may be used to determine a power metric for the power each secondary coil is receiving from the corresponding

primary coil

121 and 122 of the wireless power transfer device 110. RX controller 180 may cause communication channel units 181 and 182 to communicate power metrics via a first communication channel 751 and a second communication channel 752, respectively. For example, the first channel communication unit 181 may communicate a first power metric packet via the first communication channel 751. The first power metric packet may include a first power metric based on the power received by the first secondary coil 161. The second channel communication unit 182 may communicate the power metric packet via a second communication channel 752. The second power metric package may include a second power metric based on the power received by the first secondary coil 161.

The first channel communication unit 131 and the second channel communication unit 132 may demodulate the first and second power metric packets, respectively. In some implementations, the power metric package may include a channel ID or tag ID that uniquely identifies each transmit coil pair (or communication paths 751 and 752). TX controller 130 may measure the voltage and current of each

primary coil

121 and 122 to determine the transmit power being transmitted by each

primary coil

121 and 122. For each transmit coil pair, TX controller 130 may compare the magnitude of the transmit power to a receive power metric. The difference between the magnitude of the transmit power and the received power metric may be indicative of a power loss due to misalignment or the presence of a foreign object. For example, the foreign object 810 may absorb some of the power transmitted by the first primary coil 121. The power metric of the first secondary coil 161 may be lower than the magnitude of the transmit power measured for the first primary coil 121. If the difference exceeds the threshold, TX controller 130 may determine that foreign object 810 is present near the coil pair including first primary coil 121 and first secondary coil 161. Meanwhile, the power metric of the second secondary coil 162 may be within a threshold amount of the transmission power value of the second primary coil 122.

Other techniques for foreign object detection are possible due to the availability of different communication channels, channel IDs, or tag IDs associated with each transmission coil pair. Due to the ability to detect foreign objects at different coil pairs, unaffected coil pairs may continue while affected coil pairs may be disabled. Such flexibility and sensitivity is not possible in PC1 systems using only a single large primary coil and a single large secondary coil. Thus, the ability to use the combined power delivered by multiple PC0 transmission coil pairs may improve foreign object detection and wireless power transfer flexibility, even for wireless power receiving devices requiring PC1 power ratings.

Fig. 9 illustrates another example 900 of using multiple communication channels between an example wireless power receiving device 150 and an example wireless power transmitting device 110 in accordance with some implementations. Each transmission coil pair (represented by a primary coil and a secondary coil) may create a communication channel. This degree of freedom may be available when each

primary coil

121 and 122 has a separate power signal generator (such as a separate driver, not shown). Each channel may use ASK and FSK for forward and reverse communications, respectively. For example, the first channel communication unit 931 of the wireless power transmission apparatus 110 may have an ASK demodulator and an FSK modulator. The first channel communication unit 981 of the wireless power reception device 150 may have an ASK modulator and an FSK demodulator. Similarly, the second channel communication unit 932 of the wireless power transmission apparatus 110 may have an ASK demodulator and an FSK modulator. The second channel communication unit 982 of the wireless power reception device 150 may have an ASK modulator and an FSK demodulator. The foreign object detection technique described with reference to fig. 8 is also applicable to the example 800 in fig. 9.

Fig. 10 illustrates a flow diagram of an example process for wireless power transfer in accordance with some implementations. The flow diagram 1000 begins at block 1010. At block 1010, the process includes generating a power signal by a power signal generator and providing the power signal to a plurality of primary coils. At block 1020, the process includes transmitting, by a plurality of primary coils including at least a first primary coil and a second primary coil, a power signal as wireless power to different secondary coils of a wireless power receiving device. At block 1030, the process includes controlling an amount of power generated by the power signal generator.

Fig. 11 illustrates a flow diagram of an example process for wireless power reception, according to some implementations. The flow diagram 1100 begins at block 1110. At block 1110, the process includes receiving wireless power from a wireless power transfer device through a plurality of secondary coils. Each secondary coil is configured to receive wireless power from a different primary coil of a wireless power transfer device, the plurality of secondary coils including at least a first secondary coil and a second secondary coil. At block 1120, the process includes combining, by a power combining circuit, wireless power from the first secondary coil and the second secondary coil to form combined wireless power. At block 1130, the process includes providing the combined wireless power to at least the first load.

Fig. 12 illustrates a block diagram of an example device for use in a wireless power system, in accordance with some implementations. In some implementations, the device 1200 may be a wireless power transmitting device (such as the wireless power transmitting device 110) or a wireless power receiving device (such as the wireless power receiving device 150). The device 1200 may include a processor 1202 (possibly including multiple processors, multiple cores, multiple nodes, or implementing multithreading, etc.). Device 1200 may also include a memory 1206. The memory 1206 may be any one or more of a system memory or a possible implementation of the computer-readable media described herein. The device 1200 may also include a bus 1211 (such as PCI, ISA, PCI-Express, HyperTransport, InfiniBand, NuBus, AHB, AXI, etc.).

The device 1200 may include one or more controllers 1262 configured to manage a plurality of primary or secondary coils (such as the coil array 1264). In some implementations, the controller(s) 1262 can be distributed among the processor 1202, the memory 1206, and the bus 1211. The controller(s) 1262 may perform some or all of the operations described herein. For example, controller 1262 may be a TX controller, an RX controller, or both. The controller 1262 may also include one or more communication units (not shown) for modulating or demodulating communications sent or received by the coil array 1264.

The memory 1206 may include computer instructions executable by the processor 1202 to implement the functionality of the implementations described in fig. 1-11. Any of these functionalities may be implemented partially (or fully) in hardware or on the processor 1202. For example, the functionality may be implemented in an application specific integrated circuit, in logic implemented in the processor 1202, in a co-processor on a peripheral device or card, and so on. Additionally, implementations may include fewer or additional components not shown in FIG. 12. The processor 1202, the memory 1206, and the controller(s) 1262 may be coupled to a bus 1211. Although shown as being coupled to the bus 1211, a memory 1206 may be coupled to the processor 1202.

1-12 and the operations described herein are meant to aid in understanding examples of example implementations and should not be used to limit the potential implementations or to limit the scope of the claims. Some implementations may perform additional operations, fewer operations, operations in parallel or in a different order, and some different operations.

As used herein, a phrase referring to "at least one of … … or one or more of" … … "in a list of items refers to any combination of these items, including a single member. For example, "at least one of the following: a. b or c "are intended to cover the following possibilities: only a, only b, only c, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a and b and c.

The various illustrative components, logic blocks, modules, circuits, operations, and algorithm processes described in connection with the implementations disclosed herein may be implemented as electronic hardware, firmware, software, or combinations of hardware, firmware, or software, including the structures disclosed in this specification and their structural equivalents. The interchangeability of hardware, firmware, and software has been described generally in terms of their functionality, and illustrated in the various illustrative components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented as hardware, firmware, or software depends upon the particular application and design constraints imposed on the overall system.

The hardware and data processing apparatus used to implement the various illustrative components, logic blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose single-or multi-chip processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable Logic Device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor or any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, certain processes, operations, and methods may be performed by circuitry that is specific to a given function.

As noted above, in some aspects, implementations of the subject matter described in this specification can be implemented as software. For example, various functions of the components disclosed herein, or various blocks or steps of the methods, operations, processes, or algorithms disclosed herein, may be implemented as one or more modules of one or more computer programs. Such computer programs may include non-transitory processor or computer executable instructions encoded on one or more tangible processor or computer readable storage media for execution by or to control the operation of a data processing apparatus including components of the apparatus described herein. By way of example, and not limitation, such storage media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store program code in the form of instructions or data structures. Combinations of the above should also be included within the scope of storage media.

Various modifications to the implementations described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the scope of the disclosure. Thus, the claims are not intended to be limited to the implementations shown herein but are to be accorded the widest scope consistent with the present disclosure, principles and novel features disclosed herein.

In addition, various features that are described in this specification in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Thus, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the figures may schematically depict one or more example processes in the form of a flow diagram or flow diagram. However, other operations not depicted may be incorporated into the example processes schematically shown. For example, one or more additional operations may be performed before, after, concurrently with, or between any of the operations shown. In some cases, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

Claims

1. A wireless power transfer apparatus, comprising:

a plurality of primary coils for transferring wireless power to different secondary coils of a wireless power receiving device, the plurality of primary coils including at least a first primary coil and a second primary coil;

a power signal generator electrically connected to the plurality of primary coils and configured to selectively provide power to the plurality of primary coils;

a Transmit (TX) controller coupled with the power signal generator and the plurality of primary coils, wherein the TX controller is configured to control an amount of power provided by the power signal generator to the plurality of primary coils; and

one or more communication units communicatively coupled with the TX controller and configured to communicate with the wireless power receiving device, wherein the one or more communication units enable communication via at least a first communication channel at the first primary coil and a second communication channel at the second primary coil.

2. The wireless power transfer apparatus of claim 1, wherein the one or more communication units are configured to:

receiving a first communication from the wireless power receiving device via the first communication channel at the first primary coil, an

Receiving a second communication from the wireless power receiving device via the second communication channel at the second primary coil.

3. The wireless power transfer apparatus of claim 2, wherein the first communication and the second communication are received at different times.

4. The wireless power transfer apparatus of claim 2 wherein the first communication comprises a first identifier to identify the first communication channel, and wherein the second communication comprises a second identifier to identify the second communication channel.

5. The wireless power transfer apparatus of claim 2, wherein the TX controller is configured to detect foreign objects at either the first primary coil or the second primary coil based at least in part on the first communication or the second communication, respectively.

6. The wireless power transfer apparatus of claim 5, wherein the TX controller is configured to:

determining a first quality factor (Q-factor) of the first primary coil;

determining a second Q factor of the second primary coil;

obtaining a first reference quality value from the first communication;

obtaining a second reference quality value from the second communication; and

detecting the foreign object based on either a first comparison of the first Q factor to the first reference quality value or a second comparison of the second Q factor to the second reference quality value.

7. The wireless power transfer apparatus of claim 5, wherein the TX controller is configured to:

obtaining, from the first communication, a first received power metric with respect to wireless power received by a first secondary coil of the wireless power receiving device from the first primary coil;

obtaining, from the second communication, a second received power metric with respect to wireless power received by a second secondary coil of the wireless power receiving device from the second primary coil;

determining a first transmit power metric for the first primary coil;

determining a second transmit power metric for the second primary coil; and

detecting the foreign object based on a first comparison of the first transmit power metric to the first receive power metric or a second comparison of the second transmit power metric to the second receive power metric.

8. The wireless power transfer apparatus of any of claims 3-7 wherein the one or more communication units are further configured to transmit a third communication to the wireless power receiving apparatus via either or both of the first primary coil and the second primary coil.

9. The wireless power transfer apparatus of claim 8 wherein the first communication and the second communication are received by demodulating an amplitude load modulated signal, and wherein the third communication is communicated by modulating the wireless power using frequency modulation.

10. The wireless power transfer apparatus of claim 9 wherein the amplitude load modulated signal comprises Amplitude Shift Keying (ASK) modulation and wherein the frequency modulation comprises Frequency Shift Keying (FSK) modulation.

11. The wireless power transfer apparatus of any of claims 1-10, wherein each primary coil is configured to generate an electromagnetic field for inductive transfer of wireless power of no more than 15 watts, and wherein the plurality of primary coils collectively enable wireless power transfer of more than 15 watts.

12. The wireless power transfer apparatus of any one of claims 1-11 wherein the plurality of primary coils comprises at least four primary coils and the plurality of primary coils collectively enable wireless power transfer of at least 60 watts.

13. The wireless power transfer apparatus of any of claims 1-12, further comprising:

one or more switches electrically coupled to at least one of the plurality of primary coils, wherein the one or more switches are selectively openable by the TX controller to disable the at least one primary coil if the at least one primary coil is not transmitting wireless power to the wireless power receiving device or if a foreign object is detected between the at least one primary coil and the wireless power receiving device.

14. The wireless power transfer device of any of claims 1-13, wherein each primary coil is compatible with a zero-order power (PC 0) rating, and wherein the plurality of primary coils collectively enable wireless power transfer of a primary power (PC 1) rating.

15. The wireless power transfer apparatus of claim 14,

wherein the plurality of primary coils are configured to provide power via more than one primary coil when the wireless power receiving device has a PC1 rated power requirement, and

wherein the plurality of primary coils are configured to provide power via one primary coil when the wireless power receiving device has a PC0 rated power requirement.

16. The wireless power transfer apparatus of claim 15, further comprising:

the TX controller is configured to identify whether the wireless power receiving device has the PC0 rated power requirement or the PC1 rated power requirement based at least in part on communications received from the wireless power receiving device via at least one of the plurality of primary coils.

17. The wireless power transfer apparatus of any of claims 1-16, further comprising:

a charging surface associated with the plurality of primary coils; and

one or more alignment aids to increase a likelihood that a plurality of secondary coils in the wireless power receiving device will be correspondingly aligned with the plurality of primary coils when the wireless power receiving device is placed on the charging surface.

18. A wireless power receiving device, comprising:

a plurality of secondary coils, wherein each secondary coil is configured to receive wireless power from a different primary coil of a wireless power transfer device, the plurality of secondary coils comprising at least a first secondary coil and a second secondary coil;

a power combining circuit electrically coupled to the plurality of secondary coils and configured to combine the wireless power from the first secondary coil and the second secondary coil and provide combined wireless power to at least a first load;

a Receive (RX) controller coupled with the power combining circuit and the plurality of secondary coils; and

one or more communication units communicatively coupled with the RX controller and configured to communicate with the wireless power transfer device, wherein the one or more communication units enable communication via at least a first communication channel at the first secondary coil and a second communication channel at the second secondary coil.

19. The wireless power receiving device of claim 18, wherein the one or more communication units are configured to:

transmitting a first communication to the wireless power transfer device via the first communication channel at the first secondary coil, an

Transmitting a second communication to the wireless power transfer device via the second communication channel at the second secondary coil.

20. The wireless power receiving device of claim 19, wherein the first communication and the second communication are transmitted at different times.

21. The wireless power receiving device of claim 20, wherein the first communication comprises a first identifier to identify the first communication channel, and wherein the second communication comprises a second identifier to identify the second communication channel.

22. The wireless power receiving device of any of claims 19-21, wherein the first communication comprises a first received power metric with respect to wireless power received by the first secondary coil from a first primary coil of the wireless power transfer device, and wherein the second communication comprises a second received power metric with respect to wireless power received by the second secondary coil from a second primary coil of the wireless power transfer device.

23. The wireless power receiving device of any of claims 19-22, wherein the one or more communication units are further configured to receive a third communication from the wireless power transmitting device via either or both of the first secondary coil and the second secondary coil.

24. The wireless power receiving device of claim 23, wherein the first communication and the second communication are communicated by modulating an amplitude load modulated signal, and wherein the third communication is received by demodulating the wireless power using frequency modulation.

25. The wireless power receiving device of claim 24, wherein the amplitude load modulated signal comprises Amplitude Shift Keying (ASK) modulation, and wherein the frequency modulation comprises Frequency Shift Keying (FSK) modulation.

26. The wireless power receiving device of any of claims 17-25, wherein each secondary coil is configured to receive no more than 15 watts of wireless power via an electromagnetic field generated by a different primary coil of the wireless power transfer device, and wherein the plurality of secondary coils collectively receive more than 15 watts of wireless power.

27. The wireless power receiving device of any of claims 17-26, wherein the plurality of secondary coils comprises at least four secondary coils, and the plurality of secondary coils collectively receive at least 60 watts of wireless power.

28. The wireless power receiving device of any of claims 17-27, wherein each secondary coil is compatible with a zero order power (PC 0) standard specification, and wherein the plurality of secondary coils collectively receive wireless power of a primary power (PC 1) standard specification.

29. The wireless power receiving device of any of claims 17-28, further comprising:

a housing for the plurality of secondary coils, the housing configured to be attached to an electronic device, wherein the load comprises a battery charger of the electronic device.

30. The wireless power receiving device of any of claims 17-29, further comprising:

one or more alignment aids to increase a likelihood that the plurality of secondary coils will correspondingly align with a plurality of primary coils associated with a charging surface of the wireless power transfer device when the wireless power receiving device is placed on the charging surface.